1. Field of Invention
The present invention relates to an incidence probe, in particular for an aircraft, and more particularly a probe of this type comprising at least two pressure inlets.
2. Related Art
In known devices, these probes are mainly constituted by a rod mounted on the fuselage or on the leading edge of the wings of the aircraft and comprising different pressure inlets, pressure sensors connected to these pressure inlets and processing electronics.
In all cases, the angle of incidence i is equal, ignoring the a multiplying coefficient k, to the ratio of two pressures dp and DP calculated by the processing electronics: EQU i=k.(dp/DP)
in which dp is an incidence or disalignment pressure and DP is a dynamic pressure.
The pressures dp and DP are measured by means of relative sensors or pressure differential sensors.
In devices of this type, in order to obtain constant accuracy in the measurement of the angle of incidence over a wide range of aerodynamic speeds, the accuracy of the pressure sensors used must be increased the lower the pressures to be measured.
In fact, let us consider a probe in which, the coefficient k is equal to 40, that is to say that for an incidence of 40 degrees, the incidence pressure dp is equal to the dynamic pressure DP.
Let us assume that this probe is to be used in a range of aerodynamic speeds varying from 50 to 250 m/see and in a range of angles of incidence extending from -40 degrees to +40 degrees.
One can show that the accuracy necessary on the sensors is then of the order of 4.10.sup.-4 of the measuring range.
This leads to sensors which are precise and troublesome, only adequate at low speeds but with too high a performance at high speeds, thus inefficient or ineffective.
The present invention intends to obviate these drawbacks.